Multioption control head

ABSTRACT

A valve-operating control head for a fire extinguishing system which can be equipped to be operated by either an electrical, a pneumatic, or a mechanical fire detecting system. The control head mechanism includes a lever centrally mounted on a pivot and carrying a trigger member rotatably mounted on one end thereof. The trigger holds a rotatable spring-loaded valve-operating device against operation by engaging a pin extending from the valve-operating device. A spring extending from the control head casing holds the trigger in engagement with a ratchet wheel carried by the pivot and also tends to rotate the lever and the trigger about the pivot to move the trigger out of engagement with the pin. The trigger is held against rotation about the pivot by either holding the free end of the lever or by holding the ratchet wheel from rotating. When the control head is utilized with an electrical detecting system, a solenoid is positioned to hold the lever and when it is used with a pneumatic system a diaphragm-operated arm holds the lever. When the control head is used with a mechanical detecting system a tensioned cable extending from a fusible link is wound around the ratchet wheel to hold it from rotating.

United States Patent Hansen et al.

[54] MULTIOPTION CONTROL HEAD [72] inventors: Arne H. Hansen, New City,N.Y.; Lester Victor Hebenstreit, Bloomfield, NJ.

[73] Assignee: Walter Kidde & Company, Inc., Belleville,

221 Filed: Jan. 20, 1970 [211 Appl.No.: 4,336

[52] US. Cl... ..74/2 [51] int. Cl. ..G05g 17/00 [58] Field oiSearch..74/2, 3.52; 169/7, 42, 21, 169/19; 251/66, 68, 74

[56] References Cited UNITED STATES PATENTS 268,523 12/1882 Nesbitt..74/2 441,260 11/1890 Tyberg ..74/2 2,588,239 3/1952 Hopton.........74/2 2,872,820 2/1959 Cupedo .....74/2 2,991,658 7/ l 961 Haessler..74/2 3,174,324 3/1965 Ostertag ..74/2 3,262,323 7/1966 Fallis ..74/2

3,419,083 12/1968 Cholin ..169/42X Feb. 22, 1972 FOREIGN PATENTS ORAPPLICATIONS 103,416 1899 Germany ..74/2

Primary Examiner-Milton Kaufman Attorney-Darby & Darby [5 7] ABSTRACT Avalve-operating control head for a fire extinguishing system which canbe equipped to be operated by either an electrical, a pneumatic, or amechanical fire detecting system. The control head mechanism includes alever centrally mounted on a pivot and carrying a trigger memberrotatably mounted on one end thereof. The trigger holds a rotatablespring-loaded valveoperating device against operation by engaging a pinextending from the valve-operating device. A spring extending from thecontrol head casing holds the trigger in engagement with a ratchet wheelcarried by the pivot and also tends to rotate the lever and the triggerabout the pivot to move the trigger out of engagement with the pin. Thetrigger is held against rotation about the pivot by either holding thefree end of the lever or by holding the ratchet wheel from rotating.When the control head is utilized with an electrical detecting system, asolenoid is positioned to hold the lever and when it is used with apneumatic system a diaphragm-operated arm holds the lever. When thecontrol head is used with a mechanical detecting system a tensionedcable extending from a fusible link is wound around the ratchet wheel tohold it from rotating.

18 Claims, 10 Drawing Figures PAIENIEBFEB22 I972 3, 64-3 1 5 sum 1 OF AINVENEfiRS ARNE rm ANS LESTER v. HE BENSTREW PAENIEBFEB 22 I972 SHEET '4OF C) INIVENTORS ARNE mussn gxsm: v. Minimum a'liiii The presentinvention relates to control heads for actuating valves in fireextinguishing systems, and, more particularly, to such control headswhich are operated by fire detecting systems.

A fire extinguishing system of this type must be provided with a controlhead designed to operate in response to the output of the particularfire detecting system installed in the area to be protected.

There are three basic types of fire detecting systems, electrical,pneumatic, and mechanical, and each type produces a different kind ofoutput. ln'electrical systems, the presence of a fire alters theelectrical characteristics of a detecting unit and produces anelectricalsignal which is used to operate a device such as a solenoid.In pneumatic systems, the heat of a fire causes air expansion, forexample in a tube, and the resulting pressure increase is used to move adiaphragm or piston. In mechanical systems, a fusible element, such as alink, is connected to a tensioned cable between an anchor point and astored energy device which is allowed to operate when the link melts.

In the past it has been the practice to design a control head to beoperated by a particular type of fire detecting system. Manufactures offire extinguishing systems therefore have manufactured and stocked threedifferent types of control heads, one for use with each of the threetypes offire detecting systems.

Accordingly, it is an object of the present invention to provide animproved control head for fire extinguishing systems which is operableby different types of fire detecting systems.

Another object is to provide a single control head which is operable byelectrical, pneumatic and mechanical detecting systems and is alsomanually operable.

Another object is to provide such a control head which is operable byanother control head and which is capable of operating another controlhead.

In accordance with the present invention the foregoing objects areaccomplished by providing a control head for dispensing fluid mediumunder pressure comprising in combination a lever member having first andsecond ends mounted on a first pivot between the ends, a trigger membermounted on the first end of the lever member by means of a second pivotand extending toward the first pivot, means on the first pivot forengaging the trigger member, spring means connected to the triggermember for urging the trigger member to rotate about the second pivotagainst the engaging means and for urging the lever member to rotate inthe opposite direction about the first pivot, actuating means forreleasably holding the members against rotation about the first pivot,spring-loaded valve-operating means, and means on the trigger member forholding the valve-operating means against operation when the members areheld against rotation.

BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of theinvention has been chosen for purposes of illustration and description,and is shown in the accompanying drawings, forming a part of thespecification, wherein:

FIG. 1 is an elevational view ofa control head according to the presentinvention which is arranged to be operated by a mechanical firedetecting system.

FIG. 2 is an elevation view ofa portion of the apparatus of FIG. 1showing more clearly the basic elements of the control head.

FIG. 3 is a top view of the basic elements of the control head.

FIG. 4 is a sectional view taken along line 4-4 on FIG. 1 illustratingthe valve-operating mechanism.

FIG. 5 is a sectional view taken along line 5-5 on FIG. 1.

FIG. 6 is a fragmentary elevational view of the apparatus of FIG. 1arranged to be operated by an electrical fire detecting system.

FIG. 7 is a fragmentary elevational view of the apparatus of FIG. 1arranged to be operated by a pneumatic fire detecting system.

FIG. 8 is a fragmentary view illustrating a detail of the mechanismshown in FIG. 7.

FIG. 9 is a sectional view taken along the line 9-9 on FIG. 8.

FIG. 10 is a fragmentary elevational view ofa control head arranged tobe operated by the operation of another control head.

DETAILED DESCRIPTION Referring to the drawings in detail, there is showna control head according to the present invention which is mounted on avalve body B that is fitted to a cylinder C containing fireextinguishing agent under pressure. The control head includes agenerally rectangular casing 10,. a lever 11 pivotally mounted to thecasing, a trigger member 12 pivotally mounted on the lever 10, a ratchetassembly 14 engaging the trigger member 12, and a valve-operatingmechanism 15.

The casing 10 has sidewalls 16 and 17, a top wall 19, a bottom wall 20,and a rear wall 21. A removable cover plate (not shown) is normallyattached to the casing by means of screws which pass through holes inthe cover plate and are screwed into the threaded holes 22 provided inthe corners of the casmg.

Referring now to FIGS. 2 and 3, the ratchet assembly 14 is mounted on ashaft 24 which is journaled in a formation 25 within the casing. Thelever 11 is pivotally mounted on the shaft 24 by means of an opening 26near the center thereof through which the shaft 24 passes. The triggermember 12 is pivotally mounted on the left end (as viewed in FIGS. 1-3)of the lever by means of a bolt and nut assembly 27 which passes throughopenings in the lever and trigger member. A ratchet arm 29 having teeth30 is mounted on a spacer member 31 (FIG. 3) which is secured to thetrigger member 12.

Referring to FIGS. 1 to 3 the ratchet assembly 14 includes in additionto the shaft 24, a ratchet wheel 32, a cup-shaped drum 34, and a spacersleeve 35 (FIG. 3). The shaft 24 extends through the drum 34, the wheel32 and the sleeve 35, and is provided with a hexagonal head 36 withinthe drum to which the drum is welded. The wheel 32 is welded to theinner surface of the drum and the sleeve 35 is positioned between thewheel 32 and the formation 25. The ratchet wheel is formed with a seriesof teeth 37 which extend completely around its outer edge and intermeshwith the teeth 30 on the ratchet arm 29.

A coil spring 38 extending between a hole 39 in the trigger member andan anchor pin 40 secured to the lower casing wall 20 holds the teeth ofthe ratchet arm in engagement with the teeth of the ratchet wheel. Thisspring also urges the trigger member 12 and the lever 11 to rotatecounterclockwise about the shaft 24 to release the valve-operatingmechanism 15.

Referring to FIG. 4, the valve operating mechanism 15 includes formation41 extending upwardly from the bottom wall 20 of the casing andintersecting the formation 25, a stepped bore extending verticallythrough the formation 41 including a large diameter lower portion 42 anda smaller diameter upper portion 44, a plunger 45 having a largediameter head 46 positioned in the bore portion 42 and a small diametershaft 47 extending through the upper bore portion 44, a spring 49 in thelower bore portion 42 urging the plunger 45 downwardly, a bore 50 in theformation 25 intersecting the bore portion 44, a cylindrical actuatingmember 51 in the bore 50 journaled on a bearing 52, a pin 54 mountedeccentrically in the inner end of the member 51 and extending into ahorizontally oriented slot 55in the shaft 47 of the plunger, a bearing56 surrounding the portion of the pin 54 within the slot 55, and a pairof pins 57 and 59 (FIGS. 1-3) extending radially outwardly from thecylindrical actuating member 51. The pin 57 engages a surface 60 on theright end ofthe trigger member 12.

The operation of the basic elements of the control head can best beunderstood by reference to FIGS. 2 to 4. The valve on the fireextinguishing cylinderis designed to be opened when the plunger 45 isallowed to move downwardly under the influence of the spring 49.

The plunger is maintained in the position shown by the engagement of thepin 57 with the surface 60 of the trigger member 12 which preventsrotation of the member 51. The spring 38 urges the rotation of thetrigger member (together with the lever 11) around the shaft 24 in acounterclockwise direction so as to move the surface 60 out ofengagement with the pin 57. The trigger member is held in the positionshown either by holding the right-hand end of the lever 11 againstcounterclockwise movement by a solenoid or a pneumatically actuatedlever as described hereinafter or by holding the ratchet wheel againstsuch movement by a tensioned cable as described hereinafter. Thetensioned cable, solenoid, or pneumatically actuated lever holding thelever and trigger member from counter clockwise movement is under thecontrol of a fire detecting system. When the fire detecting systemsenses the presence of a fire, the lever and trigger member arereleased, as described hereinafter, and the lever 11, the trigger member12, and the ratchet assembly 14 rotate under the influence of the spring38. When the surface 60 moves out ofengagement with the pin 57, theplunger 45 is free to move downwardly under the action of the spring 49and the cylindrical member 51 rotates counter clockwise.

The trigger member 12 is provided with an arm 61 which as shown in FIG.3 is formed to be in alignment with the pin 59 extending from the member51. Should the member 51 or the eccentric pin 54 bind and prevent theplunger 45 from moving, the arm 61 will strike the pin 59 as the triggermember 12 rotates about the axis of the shaft 24 and drive thecylindrical member 51 into rotation to allow the plunger to move.

Referring again to FIG. 1, the tap wall 19 of the casing is providedwith an opening 62, the side wall 16 is provided with an opening 64 andthe sidewall 17 is provided with an opening 65. As shown in FIG. 1, whenthe control head is connected to be operated by a mechanical firedetecting system, a cable 66 extends downwardly through the opening 62and is wrapped around the drum 34. The cable 66 runs from the controlhead over pulleys (not shown) to the area under protection where it isconnected to a fusible link or a series of such links. The other end ofthe link or series oflinks is anchored, for example by a cable attachedto an eyebolt secured to a wall.

Before attaching the cable to the drum, the cover is removed from thecasing, the trigger member is manually placed in the position shown inFIG. 1, and a pin 67 (FIG. 5) is passed through an arcuate slot 69provided in the trigger member and is inserted in a bore 70 provided inthe casing. As shown in FIG. 5, the bore 70 extends into a formation 71and the pin 67 is provided with a reduced diameter section 72 inhorizontal alignment with the trigger member 12. When the trigger member12 is released it is rotated by the spring 38 counterclockwise until theedge of the slot 69 butts against the section 72 of the pin 67preventing the pin 67 from being withdrawn.

The cable 66 is attached to the drum 34 by passing it through a hole 74in the cylindrical wall of the drum and clamping a bead onto the end ofthe cable which is of larger diameter than the hole 74. The cable isthen tensioned by rotating the ratchet assembly counterclockwise bymeans of a wrench applied to the hexagonal head 36 of the shaft 24 or byapplying a screwdriver to a slot 75 provided in the head 36. When thetension in the cable 66 increases to the point that it begins tocounterbalance the action of the spring 38, the trigger member 12 ismoved clockwise each time the tension in the cable 66 is increased. Thetension in the cable is in creased until the slot 69 is aligned with thebore 70 so that the pin 67 can be withdrawn. The pin 67 is of sufficientlength so that the cover cannot be replaced until the pin is removedthus preventing the pin from being inadvertently left in the bore 70 toprevent the control head from functioning.

The trigger member 12 is held by the tension in the cable 66 in theposition shown in FIG. 1. When a fire occurs in the protected area, thefusible links (or one of them) melts releasing the cable 66 and allowingthe trigger member 12 to be rotated by the spring 38 to actuate thevalve-operating mechanism.

When the control head is arranged to be operated by an electrical firedetecting system, the right-hand end of the lever 11 is held against theaction ofthe spring 38 by a solenoid. The right end of the lever 11 isprovided with an upwardly facing arcuate depression 76 and, as shown inFIG. 6, the solenoid 77 is mounted to the wall 17 of the casing and isprovided with a plunger 79 which is normally seated in the depression 76of the lever 11. When the electrical fire detecting system responds tothe presence of a fire, it produces a signal which actuates the solenoidcausing the plunger 79 to retract and free the lever 11 allowing thetrigger member to rotate as previously described.

To arrange the control head to be operated by a pneumatic fire detectingsystem, a pressure sensor 80 is mounted on the top wall 19 of the casingas shown in FIG. 7. The sensor 80 includes an upwardly facing dishshaped lower body member 81 and a downwardly facing generallydish-shaped upper body member 82 providing a chamber therebetween, andan annular diaphragm 84 clamped between the members 81 and 82 to dividethe chamber into an upper portion 85 and a lower portion 86. The upperbody member 82 at one point along its outer edge has an enlargement 87provided with a threaded bore 89 for the connection of a pneumatic lineand an inlet passageway 90 connecting with the upper chamber portion 85.The member 82 is also formed with an upwardly extending peripheralflange 91 and a central upwardly extending cylindrical formation 92provided with a threaded bore 94 and a vent hole 95 at the bottom of thebore 94. A screw 96 having a stepped central bore is threaded into thebore 94. The stepped bore includes an upper large diameter portion 97containing a plug 99 of porous material and a lower smaller diameterportion 100 which places the plug 99 in fluid flow communication withthe vent hole 95. The plug 99 allows air to escape very slowly from thechamber portion 85 so as to prevent normal ambient temperature changes(which take place slowly) from producing a pressure within the chamberportion sufficient to operate the control head.

The lower body member 81 is provided with a central opening 101 inalignment with the opening 62 in the casing wall 19. A lever 102 ispivotally mounted within the casing on a formation 104 and has an arm105 extending horizontally from the pivot point to the opening 62 and anarm I06 extending downwardly at an angle from the pivot point to theright end of the lever 11. The arm 105 is provided with a verticalfinger 107 which extends upwardly through the openings 62 and 101 tocontact the diaphragm 84. The diaphragm 84 is provided with upper andlower reinforcing discs 109 and 110 on each side thereof, and the finger107 contacts the lower disc 110.

As best shown in FIGS. 8 and 9, the end of arm 106 is provided with anextension 111 which extends at right angles to the arm and is bent backupon itself to provide the U"- shaped formation shown in FIG. 9. A bar112 is pivoted within the U-shaped formation on a pin 114 and a stop pin115 extends from the arm 106 to prevent counterclockwise rotation (asshown in FIG. 8) of the bar 112. The bar 112 has a pointed lower end 116which engages a notch 117 formed in the end of the lever 11 I.

The casing 10 is provided with an internally threaded tubular formation119 extending outwardly from the upper end of the wall 17. A coil spring120 positioned within the formation 119 is connected between a screwassembly 121 threaded into the formation and a link member 122 attachedto the arm 105. The spring 120 tends to rotate the lever 102 in aclockwise direction to hold the pointed end 116 of the bar 112 firmly inthe notch 117 in the lever 11. When the lever 102 is being biased inthis direction, the bar 112 is pressed firmly against the pin 115 so asto act as an extension of the arm 106. The screw assembly 121 includes acup-shaped screw 124 having a bore 125 in the inner wall thereof and aconnecting pin 126 extending through the bore 125 and having an enlargedhead 127 within the screw 124. The force exerted by the spring 120 isadjusted by turning the screw 124, by means of screwdriver slots 129, tocontrol the diaphragm pressure required to operate the control head.

When a fire occurs in the area under protection, the air within thepneumatic tubing connected to the pressure sensor 80 is heated andexpands increasing the pressure within the upper chamber portion 85. Thepressure within the chamber portion 85 pushes the diaphragm 84 downagainst the finger 107 of the lever 102. When the diaphragm pressureovercomes the action of the spring the lever 102 begins to movecounterclockwise. Referring to FIG. 8, the rotation of the lever 102moves to the pivot pin 114 to the right allowing the bar 112 to pivotabout its point and rotate clockwise to release the lever 11 permittingthe trigger member 12 to rotate actuating the control head.

Referring once again to FIG. 1, the control head is provided with alever 130 which can be used to manually operate the control head. Thelever 130 is carried by a shaft 131 pivotally mounted in the rear wall21 of the casing and includes a vertically extending arm 132 and ahorizontally extending arm 134-. The vertically extending arm 132 isprovided with a curved cam surface 135 protruding from its left edge andengaging a forwardly extending flange 136 on the trigger member 12. Onthe lower end of the arm 132, a tab 137 is provided which extendsforwardly and is provided with a hole (not shown) for purposes describedhereinafter. The horizontal arm 134 is vertically aligned with the pin57 of the valve-operating mechanism 15. The rotatable shaft 131 isprovided with a slot 139 for receiving a handle (not shown). The coverplate previously discussed has an opening therein aligned with the shaft131 to permit use of the handle when the cover plate is in place.

When the handle is used to rotate the lever 130 clockwise, theengagement of the cam surface 135 and flange 136 forces the triggermember 12 to rotate counterclockwise. When the control head is arrangedfor operation by a mechanical fire detecting system as shown in FIG. 1,the lever 130 merely has to move the trigger member 12 far enough todisengage the teeth 30 of the ratchet arm 29 from the teeth 32 of theratchet wheel. The trigger member and the lever 11 are then free torotate about the shaft 24. When the control head is arranged foroperation by an electrical or pneumatic system wherein the lever 11 islocked against movement, the lever 130 must rotate the trigger memberabout the bolt and nut assembly 25 until the surface 60 clears the pin57. Should any elements within the valve-operating mechanism bind so asto prevent its operation, continued movement of the lever 130 will causethe right end of the arm 134 to strike the pin 57 and free themechanism.

As shown in FIGS. 1 and 10, when a second fire extinguishing cylinder isincluded in the system, the second cylinder is provided with a controlhead identical to the one described hereinabove. This second controlhead normally is not connected to the fire detecting system but ratheris connected to be operated by the operation of the first control head.The connection between the control heads is provided by a cable 140which is fastened to the pin 59 and wrapped around the member 51 of thefirst control head (FIG. 1). The cable 140 passes through the opening 65in the wall 17 of the first control head, enters the second control head(FIG. through the opening 64' and passes through the hole in the tab 137of the lever 130. The cable is pulled taught and a clamp 141 is appliedto the cable. In the second control head (FIG. 10) the trigger member12' is kept from rotating only by the engagement of the lever 130 withthe flange 136' of the trigger member. The flange 136 is pressed againstthe cam surface 135 by the action of the spring 38 producing africtional force which holds the trigger member 12' in position againstthe action ofthe spring 38'.

When the first control head is operated, the member 51 rotates clockwiseremoving the tension from the cable 140. The lever 130 in the secondcontrol head is thus released allowing the trigger member to rotateunder the influence 0f the spring 38'. The second control head may beemployed to operate a third control head in the same manner.

It will be seen from the foregoing, that the present invention providesan improved control head for fire extinguishing systems which isoperable by electrical, pneumatic and mechanical detecting systems, andin addition, is manually operable and is capable ofoperating anothercontrol head.

We claim:

1. A control head for use in dispensing fluid medium under pressurecomprising in combination a lever member having first and second ends, afirst pivot means on which said lever member is mounted between itsends, a trigger member mounted on said first end of said lever member bysecond pivot means, said trigger member having a first portion thereofextending toward said first pivot means, means on said first pivot meansfor engaging said first portion of said trigger member, spring meansconnected to said trigger member for urging said trigger member torotate about said second pivot means and to bring said first portion ofsaid trigger member into engagement against said engaging means on saidfirst pivot means and for urging said lever member to rotate in theopposite direction about said first pivot means, actuating means forreleasably holding said first portion of said trigger member inengagement with said engaging means on said first pivot means to preventsaid lever member and said trigger member from rotating about said firstpivot means, springloaded valve-operating means, means on said triggermember for holding said valve-operating means against operation whensaid first lever and said trigger members are held from rotating.

2. A control head according to claim 1 wherein said actuating means ispositioned to releasably engage said second end of said lever member tohold said lever and trigger members against rotation.

3. A control head according to claim 2 wherein said actuat ing meansincludes a diaphragm operated by fluid pressure, a lever element havinga first end contacting said diaphragm and having a second end engagingsaid second end of said lever member, and a spring attached to saidlever element to act against said diaphragm to said second end of saidlever element in contact with said lever member.

4. A control head according to claim 3 wherein said second end of saidlever member is provided with a notch therein, and said second end ofsaid lever element has a bar pivoted thereto and is provided with a stopelement to hold the bar against rotation in one direction, said stopelement being positioned to prevent rotation of said bar when said baris urged into said notch by the action of said spring upon said leverelement, said diaphragm being responsive to a change in pressure in apredetermined direction to move said lever element against said springand allow said bar to rotate in the other direction to release saidlever member.

5. A control head as in claim 2 wherein said actuating means comprisesan electrically operated means having a plunger portion which engagessaid second end of said lever member.

6. A control head according to claim 1 wherein said engaging means ofsaid first pivot means includes a wheel member rotatable on said firstpivot means, said wheel member and said trigger member havinginterengaging elements preventing relative rotation therebetween in onedirection, said actuating means being connected to said wheel member tonormally prevent said wheel member from rotating by the forcetransmitted from said spring means through said trigger member and saidlever member.

7. A control head according to claim 6 wherein said actuating meansincludes cable means secured to said wheel member and wherein saidinterengaging elements permit rotation of said wheel member in adirection to tension said cable means to hold said trigger memberagainst the action of said spring means.

8. A control head according to claim 7 wherein a drum member is securedto said wheel member and said cable means is attached to said drummember.

9. A control head according to claim 7 wherein said wheel member isrotated in a direction opposite said one direction by said spring uponrelaxation of the tension in said cable.

10. A control head according to claim 7 further comprising a stop meansfor engagement with said trigger member and another portion of saidcontrol head to prevent said trigger member from rotating about saidfirst pivot means, means on said wheel member for rotating the same toincrease the tension in said cable means as said wheel member is rotatedin said one direction, and means formed on said stop means to preventdisengagement from said trigger member until the cable has beentensioned to a predetermined degree.

11. A control head as in claim 10 wherein said stop means comprises apin having a reduced diameter section, a slot formed in said triggermember through which said pin projects to engage said other portion ofsaid control head, a portion of said trigger member surrounding saidslot for engaging said pin at its reduced diameter portion, said triggermember being moved as said cable is being tensioned by rotation of saidwheel to move said slot to a position where the pin can be withdrawnwhen said cable has been tensioned to said predetermined degree.

12. A control head according to claim 1 wherein said valveoperatingholding means on said trigger member includes a projection extendingpast said first pivot means and wherein said spring-loadedvalve-operating means includes a rotatable actuating member, a springmember for urging said rotatable actuating member to rotate, and anelement on said rotatable actuating member for engaging said projectionon said trigger member, said trigger member being rotatable about saidfirst pivot under the influence of said spring member to move saidprojection out of engagement with said projection-engaging element.

13. A control head according to claim 12 wherein saidprojection-engaging element is a pin extending radially from saidrotatable actuating member, said rotatable actuating member is providedwith a second pin extending radially therefrom, and said trigger memberis provided with a formation aligned with said second pin so as tostrike said second pin when said said rotatable actuating member doesnot rotate when said projection moves out ofengagement with said firstpin.

14. A control head according to claim 1 including a manually operablelever for engaging and rotating said trigger member about said secondpivot to release said valve-operating means.

15. A control head according to claim 17 wherein said valve-operatingmeans includes a rotatable actuating member, a spring member urging saidactuating member to rotate, and a pin extending radially from saidactuating member for engaging said trigger member, and wherein saidmanually operable lever includes a first arm for engaging said triggerand a second arm for engaging said pin in the event said actuatingmember does not rotate when said trigger member rotates about saidsecond pivot.

16. A control head according to claim 14 wherein said actuating meansincludes said manual lever, tensioned cable means, and means forreleasing said cable means, said trigger member and said manual leverbeing provided with interengaging surfaces, said manual lever having aposition wherein said surfaces are engaged so that said manual lever iscapable of holding said trigger member against the action of said springmeans, said tensioned cable being connected to said manual lever to holdsaid lever in said position.

17. A control head according to claim 16 wherein said means forreleasing said tension cable includes a valve-operating mechanism inanother control head whereby said manual lever is released to allow saidtrigger to rotate in response to the operation of the valve-operatingmechanism in said other control head.

18. A control head according to claim 1 wherein said valveoperatingholding means on said trigger member includes a projection extendingpast said first pivot means and wherein said spring loadedvalve-operating means includes a rotatable actuating member, a springmember for urging said rotatable actuating member to rotate, and anelement on said rotatable actuating member for engaging said projectionon said trigger member, a manually operable lever for engaging androtating said trigger member about said second pivot to move saidprojection out of engagement with said projection-engaging element.

\1 trigger member rotates about said first pivot in the event that

1. A control head for use in dispensing fluid medium under pressurecomprising in combination a lever member having first and second ends, afirst pivot means on which said lever member is mounted between itsends, a trigger member mounted on said first end of said lever member bysecond pivot means, said trigger member having a first portion thereofextending toward said first pivot means, means on said first pivot meansfor engaging said first portion of said trigger member, spring meansconnected to said trigger member for urging said trigger member torotate about said second pivot means and to bring said first portion ofsaid trigger member into engagement against said engaging means on saidfirst pivot means and for urging said lever member to rotate in theopposite direction about said first pivot means, actuating means forreleasably holding said first portion of saId trigger member inengagement with said engaging means on said first pivot means to preventsaid lever member and said trigger member from rotating about said firstpivot means, spring-loaded valve-operating means, means on said triggermember for holding said valve-operating means against operation whensaid first lever and said trigger members are held from rotating.
 2. Acontrol head according to claim 1 wherein said actuating means ispositioned to releasably engage said second end of said lever member tohold said lever and trigger members against rotation.
 3. A control headaccording to claim 2 wherein said actuating means includes a diaphragmoperated by fluid pressure, a lever element having a first endcontacting said diaphragm and having a second end engaging said secondend of said lever member, and a spring attached to said lever element toact against said diaphragm to said second end of said lever element incontact with said lever member.
 4. A control head according to claim 3wherein said second end of said lever member is provided with a notchtherein, and said second end of said lever element has a bar pivotedthereto and is provided with a stop element to hold the bar againstrotation in one direction, said stop element being positioned to preventrotation of said bar when said bar is urged into said notch by theaction of said spring upon said lever element, said diaphragm beingresponsive to a change in pressure in a predetermined direction to movesaid lever element against said spring and allow said bar to rotate inthe other direction to release said lever member.
 5. A control head asin claim 2 wherein said actuating means comprises an electricallyoperated means having a plunger portion which engages said second end ofsaid lever member.
 6. A control head according to claim 1 wherein saidengaging means of said first pivot means includes a wheel memberrotatable on said first pivot means, said wheel member and said triggermember having interengaging elements preventing relative rotationtherebetween in one direction, said actuating means being connected tosaid wheel member to normally prevent said wheel member from rotating bythe force transmitted from said spring means through said trigger memberand said lever member.
 7. A control head according to claim 6 whereinsaid actuating means includes cable means secured to said wheel memberand wherein said interengaging elements permit rotation of said wheelmember in a direction to tension said cable means to hold said triggermember against the action of said spring means.
 8. A control headaccording to claim 7 wherein a drum member is secured to said wheelmember and said cable means is attached to said drum member.
 9. Acontrol head according to claim 7 wherein said wheel member is rotatedin a direction opposite said one direction by said spring uponrelaxation of the tension in said cable.
 10. A control head according toclaim 7 further comprising a stop means for engagement with said triggermember and another portion of said control head to prevent said triggermember from rotating about said first pivot means, means on said wheelmember for rotating the same to increase the tension in said cable meansas said wheel member is rotated in said one direction, and means formedon said stop means to prevent disengagement from said trigger memberuntil the cable has been tensioned to a predetermined degree.
 11. Acontrol head as in claim 10 wherein said stop means comprises a pinhaving a reduced diameter section, a slot formed in said trigger memberthrough which said pin projects to engage said other portion of saidcontrol head, a portion of said trigger member surrounding said slot forengaging said pin at its reduced diameter portion, said trigger memberbeing moved as said cable is being tensioned by rotation of said wheelto move said slot to a position where the pin can be withdrawn when saidcable has been tensioned to said predetermined degree.
 12. A conTrolhead according to claim 1 wherein said valve-operating holding means onsaid trigger member includes a projection extending past said firstpivot means and wherein said spring-loaded valve-operating meansincludes a rotatable actuating member, a spring member for urging saidrotatable actuating member to rotate, and an element on said rotatableactuating member for engaging said projection on said trigger member,said trigger member being rotatable about said first pivot under theinfluence of said spring member to move said projection out ofengagement with said projection-engaging element.
 13. A control headaccording to claim 12 wherein said projection-engaging element is a pinextending radially from said rotatable actuating member, said rotatableactuating member is provided with a second pin extending radiallytherefrom, and said trigger member is provided with a formation alignedwith said second pin so as to strike said second pin when said triggermember rotates about said first pivot in the event that said rotatableactuating member does not rotate when said projection moves out ofengagement with said first pin.
 14. A control head according to claim 1including a manually operable lever for engaging and rotating saidtrigger member about said second pivot to release said valve-operatingmeans.
 15. A control head according to claim 17 wherein saidvalve-operating means includes a rotatable actuating member, a springmember urging said actuating member to rotate, and a pin extendingradially from said actuating member for engaging said trigger member,and wherein said manually operable lever includes a first arm forengaging said trigger and a second arm for engaging said pin in theevent said actuating member does not rotate when said trigger memberrotates about said second pivot.
 16. A control head according to claim14 wherein said actuating means includes said manual lever, tensionedcable means, and means for releasing said cable means, said triggermember and said manual lever being provided with interengaging surfaces,said manual lever having a position wherein said surfaces are engaged sothat said manual lever is capable of holding said trigger member againstthe action of said spring means, said tensioned cable being connected tosaid manual lever to hold said lever in said position.
 17. A controlhead according to claim 16 wherein said means for releasing said tensioncable includes a valve-operating mechanism in another control headwhereby said manual lever is released to allow said trigger to rotate inresponse to the operation of the valve-operating mechanism in said othercontrol head.
 18. A control head according to claim 1 wherein saidvalve-operating holding means on said trigger member includes aprojection extending past said first pivot means and wherein said springloaded valve-operating means includes a rotatable actuating member, aspring member for urging said rotatable actuating member to rotate, andan element on said rotatable actuating member for engaging saidprojection on said trigger member, a manually operable lever forengaging and rotating said trigger member about said second pivot tomove said projection out of engagement with said projection-engagingelement.